Loss of muscle mass of the lower limbs and of the spine extensors markedly impairs locomotor ability and spine stability in old age. In this study, we investigated whether 8 w of neuromuscular electrical stimulation (NMES) improves size and architecture of the lumbar multifidus (LM) and vastus lateralis (VL) along with locomotor ability in healthy older individuals. Eight volunteers (aged 65 ≥ years) performed NMES 3 times/week. Eight sex- and age-matched individuals served as controls. Functional tests (Timed Up and Go test (TUG) and Five Times Sit-to-Stand Test (FTSST)), VL muscle architecture (muscle thickness (MT), pennation angle (PA), and fiber length (FL)), along with VL cross-sectional area (CSA) and both sides of LM were measured before and after by ultrasound. By the end of the training period, MT and CSA of VL increased by 8.6% and 11.4%, respectively. No significant increases were observed in FL and PA. LM CSA increased by 5.6% (left) and 7.1% (right). Interestingly, all VL architectural parameters significantly decreased in the control group. The combined NMES had a large significant effect on TUG (r = 0.50, p = 0.046). These results extend previous findings on the hypertrophic effects of NMES training, suggesting to be a useful mean for combating age-related sarcopenia.

Department of Neuroscience Imaging and Clinical Science Università degli Studi G d'Annunzio Chieti e Pescara 66100 Chieti Italy

Department of Psychological Health and Territorial Sciences University G d'Annunzio of Chieti Pescara 66100 Chieti Italy

Faculty of Physical Education and Sport Charles University 16252 Prague Czech Republic

Interuniversitary Institute of Myology 66100 Chieti Italy

Neuromuscular Physiology Laboratory Department of Biomedical Sciences University of Padova 35122 Padova Italy

SMART Lab Bioengineering and Biomedicine Company Srl 66020 Pescara Italy

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